U.S. drug reviewers questioned the value of preventing blood clots with Sanofi SA's semuloparin injection for cancer patients receiving chemotherapy. The Food and Drug Administration staff said only a small number of people in the clinical trials for semuloparin actually had issues with clotting, and most people died from other problems. "These findings call into question the clinical value of semuloparin in the proposed clinical setting," the FDA reviewers said in documents posted online on Monday.